JPH0561969A - Coordinate data expressing method - Google Patents

Abstract

PURPOSE:To compress the amount of data with numeric value storing continuous line segments by expressing the end X-coordinate of the line segment when a second line segment is in parallel with the X-axis, and expressing the end Y-coordinate when it is in parallel with the Y-axis. CONSTITUTION:When both two continuous line segments are in parallel with the X-axis or the Y-axis, the two line segments continuing with coordinate data of five numeric values can be expressed by the end X-coordinate of the line segment when a second line segment is in parallel with the X-axis and the end Y-coordinate of the line segment when it is in parallel with the Y-axis. In such a manner, the coordinate data of a first line segment is outputted as start coordinate and end coordinate to a memory device in sequence of X1-X2. The start coordinate of the second line segment shows the end coordinate of the first line segment, and second coordinate X2=X3, therefore, it can be Judged that the line segment is in parallel with the Y-axis, and the end Y-coordinate Y3 is added on the first line segment data, and the two line segments are expressed in the coordinate data of five numeric values X1-Y3. Thereby, the amount of data can be reduced from 2(n+1) on a conventional side to (n+3).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate data representation method, and more particularly to a coordinate data representation method for processing continuous line segment coordinate data by a computer.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing an example of a conventional coordinate data expression method, FIG. 3 (a) shows a continuous line segment parallel to a coordinate axis, and FIG. 3 (b) shows that of FIG. The line segment data is shown.
When n line segments composed of the X coordinate and the Y coordinate are continuous, n + 1 coordinate data representing the line segment are required, and each coordinate is composed of the X coordinate and the Y coordinate. 2 (n + 1) pieces of coordinate data are required.

[0003]

In this conventional coordinate data representation method, since 2 (n + 1) coordinate data are required to store n continuous line segment data, a large number of continuous line data are required. There is a drawback in that a large storage capacity is required to store minute coordinate data.

[0004]

According to the coordinate data representation method of the present invention, when the first and second continuous line segments on the two-dimensional Euclidean coordinate system are parallel to the X axis or the Y axis, the first As the coordinate data of the line segment, the starting point X coordinate and the Y coordinate and the end point X coordinate and the Y coordinate are expressed, and when the second line segment is parallel to the X axis, the ending point X coordinate of the line segment is expressed. , If the second line segment is parallel to the Y axis, it represents the end point Y coordinate of the line segment.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a diagram for explaining one embodiment of the present invention, and FIG. 2 is a flow chart for explaining this embodiment.

In this embodiment, continuous two line segments are all X
When parallel to the axis or the Y-axis, the starting point X coordinate and Y coordinate and the ending point X coordinate and Y coordinate of the coordinate data of the first line segment are stored to represent one line segment data. The second line segment is X
If it is parallel to the axis, the end point X coordinate of the line
When parallel to the axis, the end point Y coordinate of the line segment expresses two continuous line segments with coordinate data of five numerical values.

The coordinate data of the second line segment is judged to be parallel to the Y axis if the X coordinate of the start point and the X coordinate of the end point of the line segment are the same, and the Y coordinate of the start point and the Y coordinate of the end point are the same. If there is, make it parallel to the X axis.

In FIG. 1, (a) shows a continuous line segment to be processed, and (b) shows the coordinate data in (a).

In FIG. 2, in step 1, it is determined whether the line segment data to be processed is the first line segment. In step 2, if it is the first line segment, the start point coordinates and end point coordinates of the line segment are output to the storage device. In step 3, it is determined whether the second continuous line segment is parallel to the X-axis or Y-axis coordinate axis based on whether the start point X coordinate and the end point X coordinate or the start point Y coordinate and the end point Y coordinate are the same. In step 3, if the line segment is parallel to the X axis, the X coordinate of the end point of the line segment is output to the storage device. In step 4, the line segment is Y
If it is parallel to the axis, the Y coordinate of the end point of the line segment is output to the storage device. In step 5, if there is a next continuous line segment, the process is repeated in step 6, and if there is no line segment, the process ends.

In this way, in the coordinate data of the first line segment, the start point coordinates and end point coordinates are X1, Y1, X2, Y2.
To the storage device in this order. The starting point of the second line segment is
The coordinates of the end point of the first line segment, and the second X2 = X3
Therefore, the line segment is determined to be parallel to the Y axis, and the end point Y coordinate (Y3) is added to the first line segment data,
By expressing the two line segments by the coordinate data of five numerical values (X1, Y1, X2, Y2, Y3), 2 (n +) of the conventional example is obtained.
The number of data can be reduced from 1) to n + 3.

[0012]

As described above, the present invention has an effect that the number of numerical data stored in the storage device for consecutive n line segments parallel to the X axis or the Y axis is compressed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the present embodiment.

FIG. 3 is a diagram showing an example of a conventional coordinate data expression method.

[Explanation of symbols]

 X1-X8 X-axis data Y1-Y8 Y-axis data

Claims (1)

[Claims] 1. When the first and second continuous line segments on the two-dimensional Euclidean coordinate system are parallel to the X axis or the Y axis,
A start point X coordinate and a Y coordinate and an end point X coordinate and a Y coordinate are expressed as the coordinate data of the first line segment, and when the second line segment is parallel to the X axis, an end point X coordinate of the line segment. Is expressed, and when the second line segment is parallel to the Y-axis, the end point Y coordinate of the line segment is expressed.